There are many applications in which lifts, arms, counter-balances, and force and torque providing mechanisms may be useful. Mechanisms such as these can be used to raise and lower a variety of items including, but not limited to, the examples listed below:                video monitors of all sizes        furniture work surfaces        production assembly tools        work load transfer equipment        kitchen cabinets        vertically oriented exercise equipment        robot control devices        windows        
These mechanisms can also be used to provide forces and torques in other orientations (e.g., horizontal or radial). Examples of such applications include, but are not limited to:                continuous constant force feeding systems for machine tools        horizontally oriented exercise equipment        drawer closing applications        door closing application        
One application for such a mechanism is the support of a display monitor for a personal computer. Personal computers and/or display monitors are often placed directly on a desk or on a computer case. However, to increase desk space, or to respond to the ergonomic needs of different operators, computer monitors are sometimes mounted on elevating structures. Alternatively, monitors are mounted to a surface such as a wall, instead of placing the monitor on a desk or a cart.
However, personal computers and/or display monitors are often used by multiple operators at different times during a day. In some settings, one computer and/or monitor may be used by multiple people of different sizes and having different preferences in a single day. Given the differences in people's size and differences in their preferences, a monitor or display adjusted at one setting for one individual is highly likely to be inappropriate for another individual. For instance, a child would have different physical space needs than an adult using the same computer and monitor.
In addition, operators are using computers for longer periods of time which increases the importance of comfort to the operator. An operator may choose to use the monitor as left by the previous user despite the discomfort, annoyance and inconvenience experienced by a user who uses settings optimized for another individual, which may even result in injury after prolonged use.
Moreover, as monitors grow in size and weight, ease of adjustability is an important consideration. For monitors requiring frequent adjustment, adjustability for monitors has been provided using an arm coupled with gas springs, where the arm is hingedly coupled with the desk or a vertical surface. However, the gas springs are costly and wear out over time. In addition, the gas springs require a significant amount of space, for instance arm length, which can be at a premium in certain applications, such as in hospitals.
Thus, there is a need for a support are that is less costly to manufacture and maintain, has increased reliability, allows easy adjustability, is scalable to many different sized loads, is adaptable to provide a long range of travel, and is adaptable to provide constant support force as the load is being positioned.